In regard to a control device of a conventional television broadcast receiver, a method for shortening a development period, during which a plurality of television broadcast receivers different in specifications are developed for a short period, is as follows. That is, the method includes to provide a control device of a television broadcast receiver with an application microprocessor serving to control all aspects of display and an additional function and a functional microprocessor depending on the hardware of a receiver, thereby, to make the hardware managed by the functional microprocessor transparent to the application microprocessor. Therefore, there are known methods for preventing the occurrence of a failure depending on the hardware of a receiver and shortening the development period. One of the methods is disclosed in, for example, Japanese Laid-Open Patent No. H10-136274.
However, in the above conventional control device, the functional microprocessor has no display means. As a result, the application microprocessor also control OSD display which depends on hardware designed for adjustments in a factory, in a market, etc., and thus the application microprocessor have a hardware-dependent portion, which poses a problem such that the control device is inadequate in its independency.